• Journal of the Korean Institute of Gas
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• v.20 no.6
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• pp.43-49
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• 2016

In this paper, purpose of study is emissions characteristics according to effects of heating value variations of CNG fuel in a dual-fuel engine fueled by diesel and natural gas. For heating value variation of CNG fuel, nitrogen gas was mixed with pure CNG fuel. So the higher heating value was changed from $10,400kcal/Nm^3$ to $9,400kcal/Nm^3$. Under one condition of CNG substitution rate was fixed at 80%, diesel fuel was injected at a fixed injection timing of 16 CAD BTDC and fuel pressure was also fixed at 110 MPa. The condition of tested engine was 1800 rpm and 500Nm. Emissions were sampled in exhaust pipe was located at downstream turbocharger. As a result, emissions characteristics were checked in heating value variations of CNG fuel with mixed nitrogen gas THC, $CH_4$ and CO emissions decreased and NOx and $CO_2$ increased.

• New & Renewable Energy
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• v.9 no.4
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• pp.40-50
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• 2013

This study was performed to investigate the potential of torrefied tulip tree (TT) for the production of pellets. For this purpose, chemical composition and fuel characteristics of torrefied TT were examined. In addition, pellets were fabricated by using sawdust of torrefied TT chip, and durability of the pellet was measured. Lignin content of torrefied TT was higher than that of non-torrefied TT, and increased with the increases of torrefaction temperature and time. Fuel characteristics of torrefied TT were affected by torrefied conditions, and the characteristics were influenced more by torrefaction temperature than by torrefaction time. Higher heating value (HHV) and ash content (AC) of torrefied tulip tree increased with increasing torrefaction temperature, and the values were much higher than HHV and AC values of non-torrefied TT. Durability of pellets fabricated with $230^{\circ}C$- and $250^{\circ}C$-torrefied TT was higher than that of $270^{\circ}C$-torrefied TT, and the value exceeded the minimum requirement (-97.50%) of the 1st-grade pellet standard designated by Korea Forest Research Institute. Based on the results, torrefaction treatment of $250^{\circ}C/50min$ to TT might be a optimal condition for the production of TT pellets considering the mass balance and fuel characteristics of TT as well as the durability of the pellets. Thus, it is confirmed that torrefied TT can be used as a raw material for the production of bio-pellets.

• Journal of Power System Engineering
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• v.19 no.4
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• pp.69-75
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• 2015

In this study, the characteristics of heating performance of a high-performance air-cooled heat pump with vapor-injection(VI) cycle using re-heater was investigated experimentally. Devices used in the experiment is consist of a VI compressor, condenser, oil separator, refrigerant (economizer outlet refrigerant) re-heater, economizer, evaporator. And R410A was used as a working fluid. The experiment was conducted with two cycles(cycles A and B) for investigating heating performance. In case of cycle B, heat exchange was conducted by re-heater between outlet refrigerant of compressor and suction refrigerant of the VI system(Fig.1, re-heater). But the re-heater was not used in case of cycle A. As a result of this experiment, discharge temperature of refrigerator in compressor was shown higher value, when the cycle B was conducted, because of the heat exchange between suction refrigerant of VI cycle and outlet refrigerant of compressor in the re-heater than cycle A that was not use re-heater. it means that liquid hammer and the decrement of heating performance can be decreased by using re-heater. Also, Heating coefficient of performance(COPh) was shown about 2.98 in Cycle B which was 4% higher than Cycle A and from these results, It was confirmed that the improvement of the heating performance of heat pump with VI cycle can be achieved by applying re-heater.

• Textile Coloration and Finishing
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• v.30 no.3
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• pp.216-226
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• 2018

The combination dyeing have been attempted to get the various color. The objective of this research was to study the color developing effects on cotton fabrics dyed with persimmon, catechu and combination of the both by heat treatment process. These dye were applied on bleached cotton fabrics for the dyeing before post mordanting with aluminium potassium sulfate, copper sulfate, and iron sulfate. The various color changes on cotton fabric were measured by color spectrophotometer. The heat treatment of temperature around $150^{\circ}C$ for an hour can reach the highest color developing. The dyed fabrics with mordanting were heated for specific time period, which was compared without the mordanting. The post mordanted fabrics showed that more various colors can be obtained using combination dyeing. K/S values of dyed fabrics with Al, Fe, and Cu mordants were higher than the cases without mordants. The Cu mordanted fabric showed very effective color developing by the heating process. The fabrics dyed with catechu lowered L* value with little changes in a* and b* values, while the a* and b* values became higher with heat treatment. The fabrics dyed with persimmon has the lowest L* value and more changes in a*, b* value with heating process. Therefore, K/S values can be increased effectively by the combination dyeing of persimmon and catechu. Colorfastness to washing in color change was grade 2-3 in non-mordanted fabric, and grade 3 in mordanted fabric. Lightfastness of the dyed fabrics was above grade 4.

• Korean Journal of Agricultural Science
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• v.38 no.4
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• pp.619-624
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• 2011

The calorific value is the most significant factor in woody biomass utilization. We measured the calorific value by the wood parts (debarked parts and bark) and moisture content for 3 major tree species (Larix kaempferi, Pinus koraiensis, and Pinus rigida). Results showed that the calorific value decreased exponentially as the moisture content increased regardless of tree species and the wood parts. The bark had higher calorific values than woody parts (de-barked parts). In addition, Pinus koraiensis had the highest calorific values among 3 study species.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.44 no.4
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• pp.362-369
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• 2008

The snow melting system by electric heating wires which is adopted in this research is a part of road facilities to keep surface temperature of the road higher than freezing point of water for melting the snow accumulated on it. The electric heating wires are buried under paved road at a certain depth and operated automatically and manually. Design theory, amount of heating, and installation standard vary according to economic situation, weather condition, installation place and each country applying the system. A main purpose of this study is figuring out the appropriate range of required heat capacity and installation depth and pitch for solving snowdrifts and freezing problems with minimum electric power consumption. This study was performed under the ambient air temperature($-2^{\circ}C$, $-5^{\circ}C$), the pitches of the electric heating wires(200 mm, 300 mm), heating value($250\;W/m^2$, $300\;W/m^2$, $350\;W/m^2$).

• The Korean Journal of Food And Nutrition
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• v.16 no.2
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• pp.130-137
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• 2003

The squid had not been utilized for gel products because of its lower gel forming ability. The objectives of this study were as followed; 1) the optimum heating condition on squid meat paste products and 2) the optimum added level for jelly strength of squid meat paste products. Optimum heating conditions of squid meat kamaboko were as followed; setting(pre-heating) at 15$^{\circ}C$ or 55$^{\circ}C$ for 2 hours and heating at 9$0^{\circ}C$ for 60 minutes. The additives examined were as follows; 20mM EDTA, 10mM PMSF, 5 $\mu$mol/100g TGase, 0.2% potassium bromate, 2% collagen, 2% sucrose ester of stearic acid and 1% egg shell powder. The effects of additives on jelly strength were observed as follow, in descending order; 10mM of PMSF>5 $\mu$mo1/100g of TGase>0.2% of potassium bromate>20mM of EDTA. But sucrose ester of stearic acid and 1% egg shell powder were no effect. The solvents examined were as follows; n-amyl alcohol, n-butyl alcohol, n-hexyl alcohol, ethyl alcohol, ethylene glycol, propylene glycol and glycerin glycol. It showed that high jelly strength as 787gㆍcm for 3% of n-butyl alcohol and 749gㆍcm for 3% of n-amyl alcohol. To adding 5% of n-butyl alcohol and n-amyl alcohol, gave the highest jelly strength and water holding capacity(WHC). Effect of alcohol on jelly strength appeared higher value at added 5% of n-butyl alcohol than n-amyl alcohol, and flying squid product was higher than jumbo squid product.

• Korean Journal of Food Science and Technology
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• v.43 no.6
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• pp.711-718
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• 2011

Effects of heating conditions and seed roasting on the lipid oxidation and antioxidants of perilla seeds were studied. Perilla seeds, that were unroasted or roasted at $180^{\circ}C$ for 20 min, were ground and heated over steam at $100^{\circ}C/1$ atm or at $135^{\circ}C/2$ atm. Lipid oxidation was evaluated by peroxide value, conjugated dienoic acids contents, and fatty acid composition. Tocopherols and polyphenols were also determined. Lipid oxidation of perilla seeds was higher during heating at $135^{\circ}C/2$ atm than at $100^{\circ}C/1$ atm, and the oxidation rate was lower in unroasted seeds than in roasted seeds. Degradation of tocopherols and polyphenols in perilla seeds during heating was faster under high pressure and temperature, and was decreased by seed roasting. Contribution of polyphenols to the oxidative stability of perilla seeds during heating was higher than that of tocopherols, suggesting polyphenols and seed roasting as important factors in lipid oxidation of perilla seeds.

• Journal of the Korea Organic Resources Recycling Association
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• v.15 no.1
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• pp.134-142
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• 2007

In this study the physico-chemical characteristics of solid waste and the thermagravimetric analysis of waste investigated. It was found that the combustible component, water and ash were 61%, 32%, 7% respectively. The amount of combustible component was much higher than those of others. It was shown that the total carbon and hydrogen of the waste 94% and the high heating value was 2897,883(Kcal/kg). The thermagravimetric analysis showed that the weight loss of wastes occurred as temperature increased, and the rate was higher in the temperature range of $300^{\circ}C$ to $500^{\circ}C$.

• Journal of the Korean Wood Science and Technology
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• v.34 no.3
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• pp.15-21
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• 2006

The objective of this research is to develop the technique for carbonization of wood pellet and analyze a possibility for the utilization of carbonized wood pellet. The properties of wood pellet charcoals, such as density, yield, elemental composition, higher heating value, and methyleneblue adsorption, were analyzed. Wood pellet was made of sawdust of Hyunsasi-poplar, Japanese larch, Korean pine, Korean red pine, and Jolcharn-oak (serrate oak), respectively. The high density charcoal ($0.5{\sim}0.7g/cm^3$) was yielded from densified wood pellet. The carbon contents and calorific values of wood pellet charcoals were increased with the increase of carbonization temperature. The methyleneblue adsorptivity of wood pellet charcoal was similar to that of wood charcoal.